High performance Ziegler-Natta catalyst systems, processes for producing such catalyst systems, and use thereof

ABSTRACT

A catalyst system for the polymerization of olefins may include a first solid catalytic component and a second solid catalytic component. The first solid catalytic component may include: a spherical MgCl2-xROH support; a group 4-8 transition metal; and a diether internal electron donor. The second solid catalytic component may include: a spherical MgCl2-xROH support; a group 4-8 transition metal; and a diether internal electron donor. The first solid catalytic component produces a propylene homopolymer having a Xylene Solubles (XS) value of greater than 2 wt %; and the second solid catalytic component produces a propylene homopolymer having a XS value of less than 2 wt %. The second catalytic component may act as an external electron donor during use, and embodiments herein do not require use of any additional external electron donors to control polymerization and reliably vary the properties of the resulting polymer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application, pursuant to 35 U.S.C. § 120, claims benefit to U.S.patent application Ser. No. 14/287,489, filed on May 27, 2014, nowissued as U.S. Pat. No. 9,611,340, which, pursuant to 35 U.S.C. §119(e), claims priority to U.S. Provisional Application 61/830,322,filed on Jun. 3, 2013; and U.S. Provisional Application 61/869,364,filed on Aug. 23, 2013, all of which are herein incorporated byreference in their entirety.

FIELD OF THE DISCLOSURE

Embodiments disclosed herein relate generally to an improvedZiegler-Natta catalyst system comprising a combination of at least twosolid catalytic components with diether compounds as internal donor,where one solid catalytic component takes the role of the external donorfor controlling the stereospecificity of the polymer. In other aspects,embodiments herein relate to the use of such a catalyst system for thepolymerization of olefins.

BACKGROUND

Ziegler-Natta catalysts are generally composed of a catalyst supportmaterial and a transition metal component. The transition metalcomponent is typically a substituted group 4-8 transition metal, withtitanium, zirconium, chromium or vanadium being commonly used. Thetransition metal is often provided as a metal halide, such as TiCl₄.Ziegler-Natta catalysts are used to effectively promote the high yieldpolymerization of olefins. In the polymerization of olefins, thecatalyst is often used in combination with an organoaluminum cocatalyst.

When used to catalyze the polymerization of propylene, a thirdcomponent, an electron donor, is often used in the catalyst to controlthe stereoregularity of the polymer. The electron donor may beincorporated into the catalyst during its synthesis (an internal donor),or it can be added to the polymerization reactor during thepolymerization reaction (an external donor). In some polymerizationprocesses, both an internal donor and an external donor may be used.Various aromatic esters, diethers, succinates, alkoxysilanes andhindered amines are examples of compounds that have been used asinternal and/or external donors.

Typical external donors are alkoxysilanes, which are used to control thestereospecificity of the polymer during the polymerization process. Anindicator of the isotacticity of a polymer is the xylene solubles (XS)content. In the presence of sufficient amounts of silane, every externaldonor features a specific XS plateau, e.g. XS of 1 wt %. Thus the XS canonly be varied by depleting the system of the external donor.Unfortunately, the XS content rises steeply when decreasing the amountof silane in the polymerization and therefore adjustment on theindustrial scale is a concern. For example only a slight variation inthe silane concentration can cause an XS value of 10 wt % instead of 4wt %, which can lead to a reactor shut down. Moreover, as worst casescenario a typical catalyst containing phthalate can produce polymerwith XS values higher than 20 wt % in the absence of a silane.

One well known support material used in Ziegler-Natta catalysts isMgCl₂. The MgCl₂ material may be complexed with ethanol (EtOH). Inpreparing the catalyst, most or all of the EtOH reacts with thetransition metal halide, such as TiCl₄.

For example, U.S. Pat. No. 4,829,034 to Iiskolan describes aZiegler-Natta catalyst, and a method for making the catalyst, using aMgCl₂-xEtOH support in which x is about 3. In Iiskolan, the supportmaterial is first contacted with an internal donor, such as D-i-BP(di-isobutyl-phthalate). The support-D-i-BP complex is then combinedwith TiCl₄ to form the catalyst.

U.S. Pat. No. 6,020,279 to Uwai describes a method for making aZiegler-Natta catalyst by producing a MgClr-xEtOH support in which x=1.5to 2.1 and the support has an average particle diameter of 91 μm. Thesupport is combined with a titanium halide, such as TiCl₄, and aninternal electron donor for 10 minutes to 10 hours at 120° C. to 135° C.in the presence of an aliphatic solvent. As internal donors, esters likedi-isobutyl-phthalate (Examples) are preferred.

Due to health, environment and safety concerns in connection with theuse of phthalate-containing Ziegler-Natta catalysts for the productionof polymers with potential skin or food contact, a second driver todevelop new Ziegler-Natta catalysts is the need to provide non-phthalatecatalyst versions that produce polymers with an identical or at leastvery similar performance profile as the currently broadly usedphthalate-containing Ziegler-Natta catalysts.

Well known alternatives to Ziegler-Natta catalysts based on phthalatesas internal donors are versions where various malonates, succinates ordiether compounds are used. Unfortunately, the use of such alternativeinternal donors results in polymers with fully different performanceprofiles. As an example and a direct comparison, the use of a phthalatebased Ziegler-Natta catalyst leads to polymers with a GPC PolydispersityIndex (PI) (also referred to as Molecular Weight Distribution or Mw/Mn)in the range of 6.5 to 8, when using certain diethers as an internaldonor the polydispersity is much more narrow (4.5 to 5.5), and whenusing succinate as internal donor the polydispersity is 10 to 15(Polypropylene Handbook, 2^(nd) Edition, Editor: Nello Pasquini, CarlHanser Verlag, Munich, 2005, page 18, Table 2.1 and P. Galli, G.Vecellio, Journal of Polymer Science: Part A: Polymer Chemistry, Vol.42, 396-415 (2004), pages 404-405 and Table 1).

The molecular weight distribution is one of the most importantproperties of a polymer. By changing this parameter, the crystallinestructure and the crystallization rate of a polymer is dramaticallyinfluenced, which has impact on the convertability and usability of apolymer for a given application. As an example, for extrusionapplications like sheet, pipe, film, raffia, or thermoforming, a broadermolecular weight distribution is advantageous, while for applicationslike fiber or injection molding a narrower molecular weight distributionwould be advantageous. As being accustomed to processing polymersproduced with phthalate based Ziegler-Natta catalysts, the convertersinsist in molecular weight distributions typically produced by suchcatalysts and expect that phthalate free Ziegler-Natta catalysts delivera similar molecular weight distribution. Unfortunately, state of the artdiether based catalysts deliver polymers where the molecular weightdistribution is too narrow while succinate based catalysts deliverpolymers where the molecular weight distribution is far too broad.

The xylene solubles (XS) content is another very important property of apolymer, and is an indicator for the stereospecificity of a polymer. Bychanging this parameter, the crystalline structure and thecrystallization rate ofa polymer is dramatically influenced as well,which has impact on the usability of a certain polymer for a givenapplication, as stiffness and toughness of polymer resins as well astheir behavior during processing, are widely dominated by the content ofxylene solubles (XS).

As external donors, alkoxysilanes are broadly used. These compoundsregulate the stereospecificity of the polymer and thus the amount of thexylene soluble content (XS) generated in the polymerization. The rangeof such xylene soluble contents (XS) is typically between about 1 and 6wt % and depends on the designated application field for the polymer. Asan example, in the case of polymers used in the field of filmapplications, such as biaxially oriented films (BOPP), the XS should behigh (3 wt % up to 6 wt %). In the case of certain injection moldingapplications, the XS content of homo polymer resins or of the homopolymer part of heterophasic impact co-polymers should be as low aspossible, preferably lower than 1.5 wt %, most preferably 1 wt % or evenlower. Other important grades require XS values between 2 wt % and 3 wt%, such as for use in applications like fiber, raffia, thermoforming andthin wall injection molding. As accustomed to processing polymers whichare produced with phthalate based Ziegler-Natta catalysts, theconverters insist in xylene soluble contents typically produced by suchcatalysts and expect that phthalate free Ziegler-Natta catalysts delivera similar xylene solubles range.

Unfortunately, state of the art diether based catalysts deliver polymerswhere the xylene solubles content is high, and when external donors likesilanes are used to reduce the amount of xylene solubles, thetechnically possible reduction is low, and as a side effect the catalystproductivity drops dramatically. As a typical example a diether catalystwithout addition of an external donor produces a polymer with a xylenesoluble content of 4 wt %. Using the same diether catalyst together withan external donor, the xylene soluble content in the polymer can bereduced to about 2 wt %, but at the same time the catalyst productivityis reduced from 30 kg polymer/g catalyst to 15 kg polymer/g catalyst.Xylene solubles of less than 2 wt % and above 4 wt % are out of reachand accordingly, such catalysts can be used for special applicationsonly, but cannot be used as universal catalysts covering the wholexylene soluble range typical of the numerous grades manufactured by apolymer producer. As a consequence, today diether catalysts are nichecatalysts and are used for the production of specialty polymers likefiber grades where the combination of a narrow molecular weightdistribution in combination with a fixed amount of xylene solubles ofabout 2.5 wt % is of certain value.

SUMMARY OF THE DISCLOSURE

Embodiments disclosed herein provide non-phthalate Ziegler-Nattacatalyst systems comprising a combination of at least two solidcatalytic components with diether compounds as internal donor for thepolymerization and copolymerization of olefins that overcome the aboveshortcomings and provide Ziegler-Natta catalyst systems with a uniquemethod of selecting at least two solid catalytic components with diethercompounds as internal donor where the three essential components of aZiegler-Natta catalyst, the support, the transition metal component, andthe internal donor, are combined as described below. The resultingZiegler-Natta catalyst systems have unusually high activity, excellenthydrogen response and stereoselectivity, while the molecular weightdistribution is comparable to phthalate containing Ziegler-Nattacatalysts and the xylene solubles content of the polymer can be adjustedbetween 0.5 wt % and 10 wt %.

In some embodiments, the catalyst system useful for the polymerizationof olefin polymers may include a first solid catalytic component and asecond solid catalytic component. The first solid catalytic componentmay include: a MgCl₂-xROH support, where x is in the range from about 1to about 10 and wherein ROH is an alcohol or a mixture of at least twodifferent alcohols; a group 4-8 transition metal; and a diether internalelectron donor. The second solid catalytic component may include: aspherical MgCl₂-xROH support, where x is in the range from about 1 toabout 10 and wherein ROH is an alcohol or a mixture of at least twodifferent alcohols; a group 4-8 transition metal; and a diether internalelectron donor. The first solid catalytic component produces a propylenehomopolymer having a Xylene Solubles (XS) value of greater than 2 wt %;and the second solid catalytic component produces a propylenehomopolymer having a XS value of less than 2 wt %.

The solid catalytic components may be formed according to embodimentsherein using a MgCl₂-xROH support, where R is a linear, cyclic orbranched hydrocarbon unit with 1-10 carbon atoms and where ROH is analcohol or a mixture of at least two different alcohols; and where x hasa range of about 1.5 to about 6.0. In some embodiments, ROH is ethanolor a mixture of ethanol and a higher alcohol with R being a linear,cyclic or branched hydrocarbon unit with 3-10 carbon atoms, such as 4-10carbon atoms, In some embodiments, x is in the range from about 2.0 toabout 4.0, such as from about 2.5 to about 3.5 or from about 2.95 toabout 3.35.

The catalytic components include a group 4-8 transition metal. In someembodiments, the group 4-8 transition metal may be a substituted group4-8 transition metal, such as titanium, zirconium, chromium or vanadium.A diether compound may be used as an internal donor.

The Ziegler-Natta catalyst systems comprising a combination of at leasttwo solid catalytic components with diether compounds as internal donoraccording to embodiments described herein may have an improved activityperformance in olefin polymerization reactions, as well as goodstereoregularity and hydrogen sensitivity, while the molecular weightdistribution is comparable to phthalate containing Ziegler-Nattacatalysts and the xylene solubles content of the polymer can be adjustedbetween 0.5 and 10 wt %.

Embodiments herein are also directed to methods of making the improvedZiegler-Natta catalyst systems comprising a combination of at least twosolid catalytic components with diether compounds as internal donor.Generally, an MgCl₂-xROH is treated with a transition metal halide, suchas TiCl₄, at a low temperature (−10° C. to +10° C.). The reactionproduct is heated to approximately 80° C. and contacted with the diethercompound. The resulting precatalyst is heated to about 105° C. and heldat that temperature for a period of time, preferably about 1 to 3 hours.The reaction mixture is filtered and washed with an organic solvent.Then the solid catalyst is preferably extracted with an organicsolvent/TiCl₄ mixture at elevated temperature. The catalyst is washedwith a solvent, such as heptane, and vacuum dried.

The improved catalyst systems described herein can be used to producepolypropylene or other polymerized olefins. The catalyst systemcomprising a combination of at least two solid catalytic components withdiether compounds as internal donor, where one catalyst takes the roleof the external donor for controlling the stereospecificity of thepolymer. Thus, there is no need for silanes to control thestereospecificity of the polymer. The catalyst system comprises (i) asolid catalytic component containing diether or a mixture of at leasttwo solid catalytic components containing diether producing homopolymers with XS values >2 wt % and (ii) a solid catalytic componentcontaining diether producing homo polymer with a XS value <2 wt %, whichtakes the role of the external donor. Adjustment of the XS values isdone by variation of the solid catalytic component (ii) which can bevaried between 0.01 wt % and 99.99 wt % relative to catalytic component(i). The catalyst systems described herein exhibit an improved activityperformance and hydrogen response, while producing polymers having goodstereospecificity and morphology, and an improved control of thestereospecificity, where the xylene solubles content of the polymer canbe adjusted between 0.5 and 10 wt %.

Other aspects and advantages will be apparent from the followingdescription and the appended claims.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram of an apparatus useful for extracting the activatedcatalyst according to embodiments herein from the pre-catalystpreparation.

FIGS. 2-5 present experimental results for catalyst systems according toembodiments herein and comparative examples.

DETAILED DESCRIPTION

In one aspect, embodiments disclosed herein relate to Ziegler-Nattacatalyst systems including a combination of at least two solid catalyticcomponents with diether compounds as internal donor useful for thepolymerization of olefins, where one solid catalytic component takes therole of the liquid external donor, e.g. alkoxysilane for controlling thestereospecificity of the polymer. The solid catalytic components withdiether compounds as internal donor provided herein are formed using aMgCl₂-xROH support, where R is a linear, cyclic or branched hydrocarbonunit with 1-10 carbon atoms like methyl, ethyl, propyl, butyl, pentyl,cyclopentyl, hexyl, cyclohexyl, heptyl or octyl and where ROH is analcohol or a mixture of at least two different alcohols, preferablywhere the ROH is ethanol or a mixture of ethanol and a higher alcoholwith R being a linear, cyclic or branched hydrocarbon unit with 3-10carbon atoms like propyl, butyl, pentyl, cyclopentyl, hexyl, cyclohexyl,heptyl or octyl, preferably 4-10 carbon atoms like butyl, pentyl,cyclopentyl, hexyl, cyclohexyl, heptyl or octyl; and where x has a rangeof about 1.5 to 6.0, preferably about 2.0 to 4.0, more preferably about2.5 to 3.5 and even more preferably 2.95 to 3.35. If ROH is a mixture ofethanol and a higher alcohol, the molar ratio of ethanol:higher alcoholis at least 80:20, preferably 90:10, most preferably 95:5.

In some embodiments, the support material may be a “spherical MgCl₂support.” The spherical MgCl₂ support may have any desired particlesize. In some embodiments, the spherical MgCl₂ support has an averageparticle size (d₅₀) of between about 10 microns to about 200 microns,preferably 20 microns and 150 microns, and more preferably between 30microns to 120 microns, and even more preferably between 40 microns to90 microns. The spherical MgCl₂ support may be produced according toU.S. Pat. No. 4,829,034 to Iiskolan and Koskinen or U.S. Pat. No.5,905,050 to Koskinen and Louhelainen by spray-cooling of a moltenMgCl₂-alcohol adduct.

The solid catalytic components with diether compounds as internal donordescribed herein include a group 4-8 transition metal, preferably agroup 4-6 transition metal. In some embodiments, the Group 4-8transition metal may be at least one of titanium, zirconium, hafnium,tantalum, niobium, rhenium, vanadium, chromium, molybdenum, tungsten,manganese, iron, ruthenium, and osmium. In preferred embodiments, thecatalyst incorporates Ti, Zr, V or Cr, and most preferably Ti. Thetransition metal is typically provided in a halogenated form, such as achloride, bromide or iodide. Titanium chloride is particularlypreferred.

The solid catalytic components with diether compounds as internal donormay be made by contacting the spherical MgCl₂ support with thetransition metal component in a reactor at a low temperature, preferably+10° C. or less, with stirring. The reactor may be charged with thespherical MgCl₂ support and the transition metal component in eitherorder, i.e. the spherical MgCl₂ support may be added first and then thetransition metal component may be added, or vice versa but the additionof the spherical MgCl₂ support to the transition metal component ispreferred. The transition metal component can be diluted with analiphatic or aromatic organic solvent, preferably an aliphatichydrocarbon, most preferably a linear aliphatic hydrocarbon like heptaneor a mixture of branched hydrocarbons like ISOPAR-H. The spherical MgCl₂support is added to the reactor over a period of time, preferablybetween about 4 minutes to about 300 minutes. The molar ratio of the Mgof the spherical MgCl₂ support to the transition metal is between 1:100and 1:5, preferably between 1:50 and 1:5, and most preferably between1:25 and 1:5.

The reaction product of the spherical MgCl₂ support and the transitionmetal component is slowly heated to a pre-determined temperature ofbetween about 30° C. and 100° C. In a preferred embodiment, the reactoris heated to a temperature of between about 40° C. and 90° C. over aperiod of about 2 hours. A diether compound as internal donor is addedto the reactor when it reaches the pre-determined temperature. Thisprecatalyst is then further heated to a temperature of at least 80° C.,preferably between 100° C. and 125° C., more preferably between 100° C.and 110° C. and held at that temperature for a predetermined period oftime, preferably between about 10 minutes and three hours. The resultingmixture is then filtered, in some embodiments while still hot, toisolate the solid component. The solid component is washed with anorganic solvent and then treated at elevated temperatures using amixture of an organic solvent and the transition metal component orusing the neat transition metal component. It is preferred to apply theSoxhlet extraction method and to use a mixture of an organic solvent andthe transition metal component. The organic solvent can be an aliphaticor aromatic hydrocarbon, preferably an aromatic hydrocarbon and mostpreferably ethylbenzene which has the same boiling point of 136° C. thanTiCl₄ which provides a constant ratio between TiCl₄ and the organicsolvent in the gas phase and in the extraction zone.

In one embodiment, the procedure to make the solid catalytic componentswith diether compounds as internal donor may include:

-   -   a) Reacting the MgCl₂-xROH with neat TiCl₄ at −30° C. to +40°        C., more preferably at −20° C. to +20° C., even more preferably        between −10° C. and +10° C. by slow addition of the TiCl₄ to the        MgCl₂-xROH/organic solvent suspension while providing constant        stirring.    -   b) Increasing the temperature of the above reaction mixture to        between about 30° C. and 100° C., preferably between about 40        and 90° C., followed by addition of a diether donor compound and        continuing to heat the mixture to at least 80° C. for about 1 to        3 hours.    -   c) Filtering the reaction mixture while still hot to obtain the        solid precatalyst.    -   d) Extracting the precatalyst using the Soxhlet extraction        method employing TiCl₄ and ethylbenzcne (at a volume ratio of        about 30:70, preferably 20:80, most preferably 10:90) for 1-5        hours, preferably 1-4 hours, most preferably 1-3 hours at a        temperature of at least 100° C., preferably 100-135° C. most        preferably 120-130° C.    -   e) Filtering and washing one or more times with a hydrocarbon        like pentane, hexane or heptane, and then drying under vacuum        and/or elevated temperature of 30-100° C., preferably 40-90° C.,        most preferably 50-80° C.

In a second embodiment, the method may include:

-   -   a) Preparing a cooled portion of neat TiCl₄ or of TiCl₄ diluted        with a non-aromatic hydrocarbon.    -   b) Reacting the neat or diluted TiCl₄ at −30° C. to +40° C.,        more preferably at −20° C. to +20° C., most preferably between        −10° C. and +10° C. by slow addition of the preformed, spherical        particles of MgCl₂-xROH while providing constant stirring.    -   c) Increasing the temperature of the reaction mixture to about        30 to 100° C., preferably to about 40 to 90° C., followed by        addition of a diether compound as internal electron donor        compound and continuing to heat the mixture to at least 80° C.        for about 1 to 3 hours.    -   d) Filtering the reaction mixture while still hot to obtain the        solid precatalyst.    -   e) Extracting the precatalyst using the Soxhlet extraction        method employing TiCl₄ and ethylbenzene (at a volume ratio of        about 30:70, preferably 20:80, most preferably 10:90) for 1-5        hours, preferably 1-4 hours, most preferably 1-3 hours at a        temperature of at least 100° C., preferably 100-135° C. most        preferably 120-130° C.    -   f) Filtering and washing one or more times with a hydrocarbon,        like pentane, hexane or heptane, and then drying under vacuum        and/or elevated temperature of 30-100° C., preferably 40-90° C.,        most preferably 50-80° C.

The Soxhlet extraction method is generally well known in the art. Forexample, as shown in FIG. 1, the precatalyst may be placed on a porousglass frit 72 and loaded into the main chamber of the Soxhlet extractor40. The Soxhlet extractor 40 is placed onto a flask 66 containing theextraction solvent 74, such as a mixture of TiCl₄ and ethylbenzene. TheSoxhlet is then equipped with a condenser 54. The solvent is heated viaheater 70 to reflux. The solvent vapor travels up a distillation arm 76,and floods into the chamber 42 housing the flit 72 containing the solidprecatalyst. The condenser 54 ensures that any solvent vapor cools, anddrips back down into the glass jacketed chamber 42 housing the solidmaterial, which may be maintained at a temperature in the range fromabout 100° C. to 135° C., most preferably 120 to 130° C. The chambercontaining the precatalyst slowly fills with warm solvent 44. Anycontaminants in the precatalyst will then dissolve in the warm solventand drip back down to the heating chamber 66, leaving behind thecatalyst. Other less preferred methods to extract the contaminants fromthe pre-catalyst include, but are not limited to washing steps with amixture of an organic solvent and TiCl₄ at a temperature of at least100° C., preferably 100-135° C., most preferably 120-130° C. The organicsolvent can be an aliphatic or aromatic hydrocarbon, preferably anaromatic hydrocarbon and most preferably ethylbenzene. While thisspecification only refers to the Soxhlet extraction method, embodimentsherein contemplate use of any extraction method that uses an organicsolvent and a transition metal component in solution. As an example, forproduction of catalyst on a commercial scale, an agitated Nutsche FilterDryer is recommended where the extraction followed by washing steps andthe drying step can be applied in only one multipurpose unit without theneed to transfer the crude solid to additional vessels.

In a third embodiment, the method may include:

-   -   a) Preparing a cooled portion of neat TiCl4 or of TiCl4 diluted        with a non-aromatic hydrocarbon.    -   b) Reacting the neat or diluted TiCl4 at −30° C. to +40° C.,        more preferably at −20° C. to +20° C., most preferably between        −10° C. and +10° C. by slow addition of the preformed, spherical        particles of MgCl2-xROH while providing constant stirring.    -   c) Increasing the temperature of the reaction mixture to about        30 to 100° C., preferably to about 40 to 90° C., followed by        addition of a diether compound as internal electron donor        compound and continuing to heat the mixture to at least 80° C.        for about 1 to 3 hours.    -   d) Filtering the reaction mixture while still hot to obtain the        solid precatalyst.    -   e) Reacting the precatalyst at least one time employing TiCl4        and ethylbenzene (at a volume ratio of about 30:70, preferably        20:80, most preferably 10:90) for 1-5 hours, preferably 1-4        hours, most preferably 1-3 hours at a temperature of at least        100° C., preferably 100-135° C. most preferably 120-130° C.    -   f) Filtering and washing one or more times with a hydrocarbon,        like pentane, hexane or heptane, and then drying under vacuum        and/or elevated temperature of 30-100° C., preferably 40-90° C.,        most preferably 50-80° C.

In a forth embodiment, the method may include:

-   -   a) Preparing a cooled portion of neat TiCl4 or of TiCl4 diluted        with a non-aromatic hydrocarbon.    -   b) Reacting the neat or diluted TiCl4 at −30° C. to +40° C.,        more preferably at −20° C. to +20° C., most preferably between        −10° C. and +10° C. by slow addition of the preformed, spherical        particles of MgCl2-xROH while providing constant stirring.    -   c) Increasing the temperature of the reaction mixture to about        30 to 100° C., preferably to about 40 to 90° C., followed by        addition of a diether compound as internal electron donor        compound and continuing to heat the mixture to at least 80° C.        for about 1 to 3 hours.    -   d) Filtering the reaction mixture while still hot to obtain the        solid precatalyst.    -   e) Reacting the precatalyst at least one time employing neat        TiCl4 for 1-5 hours, preferably 1-4 hours, most preferably 1-3        hours at a temperature of at least 100° C., preferably        100-135° C. most preferably 120-130° C.    -   f) Filtering and washing one or more times with a hydrocarbon,        like pentane, hexane or heptane, and then drying under vacuum        and/or elevated temperature of 30-100° C., preferably 40-90° C.,        most preferably 50-80° C.

Suitable diether internal donor compounds useful in embodiments hereinmay be represented by the general structure (I):R¹O—(CR⁵R⁶)_(n)—CR³R⁴—(CR⁷R⁸)_(m)—OR²  (I)wherein R¹ and R² are the same or different and are selected from thegroup consisting of a saturated or unsaturated aliphatic group of from 1to about 20 carbon atoms or an aryl group of from 6 to about 20 carbonatoms,n+m=2 to 4,R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are identical or different and are each ahydrogen atom, a linear, cyclic or branched hydrocarbon group, forexample an alkyl group of from 1 to about 20 carbon atoms, an alkenylgroup of from 2 to about 20 carbon atoms, an aryl group of from 6 toabout 20 carbon atoms, an arylalkyl group of from 7 to about 40 carbonatoms, an alkylaryl group of from 7 to about 40 carbon atoms or anarylalkenyl group of from 8 to about 40 carbon atoms and may contain oneor more hetero atoms like Si, B, Al, O, S, N or P, and/or may containhalogen atoms like F, Cl or Br, and/or the two radicals R³ and R⁴ mayform a hydrocarbon ring system. R³ and/or R⁴ are different fromhydrogen.

Preferred diether internal donor compounds useful in embodiments hereinmay be 1,3-diether compounds represented by the structure (II):R¹O—CH₂—CR³R⁴—CH₂—OR²  (II)where R¹ and R² are the same or different and are selected from thegroup consisting of a saturated or unsaturated aliphatic group of from 1to about 20 carbon atoms, more preferably an alkyl group of from 1 toabout 10 carbon atoms, even more preferably an alkyl group of from 1 to4 carbon atoms, ideally a methyl or ethyl group, most ideally a methylgroup, R³ and R⁴ are identical or different and are each a linear,cyclic or branched hydrocarbon group, for example an alkyl group of from1 to about 20 carbon atoms, an alkenyl group of from 2 to about 20carbon atoms, an aryl group of from 6 to about 20 carbon atoms, anarylalkyl group of from 7 to about 40 carbon atoms, an alkylaryl groupof from 7 to about 40 carbon atoms or an arylalkenyl group of from 8 toabout 40 carbon atoms and may contain one or more hetero atoms like Si,B, Al, O, S, N or P, and/or may contain halogen atoms like F, Cl or Br,and/or the two radicals R³ and R⁴ may form a hydrocarbon ring system.

More preferably, diether internal donor compounds useful in embodimentsherein may be 1,3-diether compounds represented by the structure (III):R¹O—CH₂—CR³R⁴—CH₂—OR²  (III)wherein R¹ and R² are identical and are selected from the groupconsisting of an alkyl group of from 1 to about 10 carbon atoms, evenmore preferably an alkyl group of from 1 to 4 carbon atoms, ideally amethyl or ethyl group, most ideally a methyl group, R³ and R⁴ areidentical or different and are each a linear, cyclic or branchedhydrocarbon group, for example an alkyl group of from 1 to about 10carbon atoms, an alkenyl group of from 2 to about 10 carbon atoms, anaryl group of from 6 to about 10 carbon atoms, an arylalkyl group offrom 7 to about 40 carbon atoms, an alkylaryl group of from 7 to about40 carbon atoms or an arylalkenyl group of from 8 to about 40 carbonatoms, and/or the two radicals R³ and R⁴ may form a hydrocarbon ringsystem, which may contain one or more hetero atoms like Si, O, S, N orP.

Examples of preferred diether electron donor compounds include: 2,2di-cyclopentyl-1,3-dimethoxypropane; 2,2di-(cyclopentylmethyl)-1,3-dimethoxypropane;2,2-di-cylohexyl-1,3-dimethoxypropane;2,2-di-(cylohexylmethyl)-1,3-dimethoxypropane;2,2-di-norbornyl-1,3-dimethoxypropane;2,2-di-phenyl-1,3-dimethoxypropane;2,2-di-phenylmethyl-1,3-dimethoxypropane;2,2-di-n-propyl-1,3-dimethoxypropane;2,2-di-isopropyl-1,3-dimethoxypropane;2,2-di-n-butyl-1,3-dimethoxypropane;2,2-di-secbutyl-1,3-dimethoxypropane;2,2-di-isobutyl-1,3-dimethoxypropane;2,2-di-n-pentyl-1,3-dimethoxypropane;2,2-di-(2-pentyl)-1,3-dimethoxypropane;2,2-di-(3-pentyl)-1,3-dimethoxypropane;2,2-di-(methylbutyl)-1,3-dimethoxypropane;2,2-di-(3-methylbut-2-yl)-1,3-dimethoxypropane;2,2-di-isopentyl-1,3-dimethoxypropane;2,2-di-n-hexyl-1,3-dimethoxypropane;2,2-di-2-hexyl-1,3-dimethoxypropane;2,2-di-3-hexyl-1,3-dimethoxypropane;2,2-di-(2-methylpentyl)-1,3-dimethoxypropane;2,2-di-(3-methylpentyl)-1,3-dimethoxypropane;2,2-di-(4-methylpentyl)-1,3-dimethoxypropane;2-tertbutyl-1,3-dimethoxypropane;2-ethyl-2-tertbutyl-1,3-dimethoxypropane;2-n-propyl-2-tertbutyl-1,3-dimethoxypropane;2-n-butyl-2-tertbutyl-1,3-dimethoxypropane;2-isobutyl-2-tertbutyl-1,3-dimethoxypropane;2-n-pentyl-2-tertbutyl-1,3-dimethoxypropane;2-isopentyl-2-tertbutyl-1,3-dimethoxypropane;2-n-hexyl-2-tertbutyl-1,3-dimethoxypropane;2-ethyl-2-isopropyl-1,3-dimethoxypropane;2-n-propyl-2-isopropyl-1,3-dimethoxypropane;2-n-butyl-2-isopropyl-1,3-dimethoxypropane;2-secbutyl-2-isopropyl-1,3-dimethoxypropane;2-isobutyl-2-isopropyl-1,3-dimethoxypropane;2-n-pentyl-2-isopropyl-1,3-dimethoxypropane;2-(2-pentyl)-2-isopropyl-1,3-dimethoxypropane;2-(3-pentyl)-2-isopropyl-1,3-dimethoxypropane;2-methylbutyl-2-isopropyl-1,3-dimethoxypropane;2-(3-methylbut-2-yl)-2-isopropyl-1,3-dimethoxypropane;2-isopentyl-2-isopropyl-1,3-dimethoxypropane;2-n-hexyl-2-isopropyl-1,3-dimethoxypropane;2-(2-hexyl)-2-isopropyl-1,3-dimethoxypropane;2-(3-hexyl)-2-isopropyl-1,3-dimethoxypropane;2-(2-methylpentyl)-2-isopropyl-1,3-dimethoxypropane;2-(3-methylpentyl)-2-isopropyl-1,3-dimethoxypropane;2-(4-methylpentyl)-2-isopropyl-1,3-dimethoxypropane;2-ethyl-2-cyclopentyl-1,3-dimethoxypropane;2-n-propyl-2-cyclopentyl-1,3-dimethoxypropane;2-isopropyl-2-cyclopentyl-1,3-dimethoxypropane;2-n-butyl-2-cyclopentyl-1,3-dimethoxypropane;2-isobutyl-2-cyclopentyl-1,3-dimethoxypropane;2-secbutyl-2-cyclopentyl-1,3-dimethoxypropane;2-n-pentyl-2-cyclopentyl-1,3-dimethoxypropane;2-(2-pentyl)-2-cyclopentyl-1,3-dimethoxypropane;2-(3-pentyl)-2-cyclopentyl-1,3-dimethoxypropane;2-methylbutyl-2-cyclopentyl-1,3-dimethoxypropane;2-(3-methylbut-2-yl)-2-cyclopentyl-1,3-dimethoxypropane;2-ethyl-2-cyclohexyl-1,3-dimethoxypropane;2-n-propyl-2-cyclohexyl-1,3-dimethoxypropane;2-isopropyl-2-cyclohexyl-1,3-dimethoxypropane;2-n-butyl-2-cyclohexyl-1,3-dimethoxypropane;2-isobutyl-2-cyclohexyl-1,3-dimethoxypropane;2-secbutyl-2-cyclohexyl-1,3-dimethoxypropane;2-n-pentyl-2-cyclohexyl-1,3-dimethoxypropane;2-(2-pentyl)-2-cyclohexyl-1,3-dimethoxypropane;2-(3-pentyl)-2-cyclohexyl-1,3-dimethoxypropane;2-methylbutyl-2-cyclohexyl-1,3-dimethoxypropane;2-(3-methylbut-2-yl)-2-cyclohexyl-1,3-dimethoxypropane; and thecorresponding 1,3-diethoxypropane analogues.

A further group of suitable diether internal donor compounds include:9,9-bis(methoxymethyl)fluorene;9,9-bis(methoxymethyl)-2,3,6,7-tetramethylfluorene;9,9-bis(methoxymethyl)-2,7-dimethylfluorene;9,9-bis(methoxymethyl)-2,7-diisoproylfluorene;9,9-bis(methoxymethyl)-2,7-ditertbutylfluorene;9,9-bis(methoxymethyl)-2,8-dimethylfluorene;9,9-bis(methoxymethyl)-3,6-dimethylfluorene;9,9-bis(methoxymethyl)-3,6-ditertbutylfluorene;9,9-bis(methoxymethyl)-3,6-diisopropylfluorene;9,9-bis(methoxymethyl)-4,5-dimethylfluorene;9,9-bis(methoxymethyl)-2-methylfluorene;9,9-bis(methoxymethyl)-4-methylfluorene;9,10-dihydro-9,9-dimethoxyanthracene;9,10-dihydro-9,9-diethoxyanthracene; 9,9-Dimethoxyxanthene;9,9-Diethoxyxanthene; and the corresponding9,9-bis(ethoxymethyl)-ananalogues.

Preferably, the diether electron donor is a compound, such as2,2-di-isobutyl-1,3-dimethoxypropane;2,2-di-isopropyl-1,3-dimethoxypropane;2,2-di-cyclopentyl-1,3-dimethoxypropane;2-isopropyl-2-isopentyl-1,3-dimethoxypropane;2-isopropyl-2-isobutyl-1,3-dimethoxypropane;2-isopropyl-2-cyclopentyl-dimethoxypropane;2-ethyl-2-tert-butyl-1,3-dimethoxypropane or the corresponding1,3-diethoxypropane analogues or 9,9-bis(methoxymethyl)fluorene or9,9-bis(ethoxymethyl)fluorene.

Also, mixtures of two or more diether internal electron donor compoundsmay be used in the preparation of the solid catalytic componentaccording to embodiments herein but the use of only one diether internaldonor compound is preferred.

When used in the preparation of the particulate solid component, thediether donor compound may be used in an amount of from about 0.01 toabout 2 mole, preferably from about 0.05 to about 0.6 mole, morepreferably from about 0.1 to about 0.3 mole for each mole of themagnesium halide compound.

The stereospecificity and thus the XS content of the polymer producedwith the solid catalytic components individually may be adjusted bysynthesis procedure and/or the amount of diether added during thesynthesis.

The Catalyst System:

In some embodiments, the catalyst systems herein may include (i) a firstsolid catalytic component containing diether or a mixture of at leasttwo solid catalytic components containing diether producing propylenehomo polymers with XS values >2 wt % and (ii) a second solid catalyticcomponent containing diether producing homo polymer with a XS value <2wt %, which takes the role of the external donor. In some embodiments,the first solid catalytic component may produce a propylene homopolymerhaving a XS value in the range from about 3 wt % to about 20 wt %; andproduces a propylene homopolymer having a XS value in the range fromabout 4 wt % to about 10 wt % in other embodiments. In some embodiments,the second solid catalytic component may produce a propylene homopolymerhaving a XS value in the range from about 0.1 wt % to about 2 wt %;produces a propylene homopolymer having a XS value in the range fromabout 0.5 wt % to about 1.5 wt % in other embodiments. In someembodiments, the first solid catalytic component and the second solidcatalytic component may individually produce a propylene homopolymerhaving a Xylene Solubles (XS) value differing by 1 wt % or greater(i.e., |XS₁-XS₂|); by 2 wt % or greater in other embodiments; and by 3,5, 7.5, or 10 wt % or greater in yet other embodiments.

Adjustment of the XS values of the resulting polymer may be performed byvarying an amount of the second solid catalytic component relative tothe first solid catalytic component. In some embodiments, the ratio ofthe first solid catalytic component to the second solid catalyticcomponent may be in the range from about 100:1 to about 1:100, such asin the range from about 100:1 to about 1:1, or in the range from about1:1 to about 1:100. In other embodiments, the ratio of the first solidcatalytic component to the second solid catalytic component may be inthe range from about 100:1 to about 1:1, such as in the range from about50:1 to 1:1 or from about 10:1 to about 1.1:1; in yet other embodiments,the second solid catalytic component may be varied between 0.01 wt % and99.99 wt % relative to the first solid catalytic component, such asbetween 1 wt % and 99 wt %, from about 5 wt % to about 95 wt %, or fromabout 10 wt % to about 90 wt % relative to the first solid catalyticcomponent. All solid catalytic components may contain the same dietheror different diethers, and in some embodiments the use of the samediether is preferred.

The catalytic systems described herein, in addition to the at least twosolid catalytic components, may further include at least one aluminumcompound as co-catalyst. In addition to the aluminum compound(s) thecatalytic systems described herein do not comprise any additionalexternal electron donor compounds, e.g. alkoxysilanes.

Examples of suitable aluminum compounds include aluminum trialkyls andderivatives thereof wherein an alkyl group is substituted by an alkoxygroup or a halogen atom, e.g., chlorine or bromine atom. The alkylgroups may be the same or different. The alkyl groups may be linear orbranched chain alkyl groups. Preferred trialkylaluminum compounds arethose wherein the alkyl groups each have 1 to 8 carbon atoms, such astrimethylaluminum, triethylaluminum, tri-isobutylaluminum,trioctylaluminum or methyldiethylaluminum. Triethylaluminum is the mostpreferred aluminum compound.

Preparation of the Catalyst System

To prepare the catalytic systems described herein, the aluminum compoundas co-catalyst may be contacted with the solid catalytic componentsseparately in any order or mixed together, normally at a temperature inthe range of from about 0° C. to 200° C., preferably from about 20° C.to about 90° C. and a pressure of from about 1 to about 100 bar, inparticular from about 1 to about 40 bar.

In a preferred embodiment, the catalyst components are stored in oil orliquid monomer, preferably liquid propylene, and are dosed directly intothe reactor together with additional liquid propylene and the aluminumcompound is dosed separately to the reactor.

Preferably, the aluminum compound co-catalyst is added in such an amountthat the atomic ratio of the aluminum compound to the transition metalof the solid catalytic components is from about 10:1 to about 800:1, inparticular from about 20:1 to about 200:1.

Polymerization

The catalytic systems described herein may be advantageously used in thepolymerization of alk-1-enes. Suitable alk-1-enes include linear orbranched C2-C10 alkenes, in particular linear C2-C10 alk-1-enes such asethylene, propylene, but-1-ene, pent-1-ene, hex-1-ene, hept-1-ene,oct-1-ene non-1-ene, dec-1-ene or 4-methylpent-1-ene. Mixtures of thesealk-1-enes may be polymerized as well.

The catalytic systems described herein, including at least two solidcatalytic components with diether compounds as internal donor and asco-catalyst an aluminum compound are excellent catalytic systems for usein the production of propylene polymers, both homo polymers of propyleneas well as co-polymers of propylene and one or more further alk-1-eneshaving up to 10 carbon atoms. The term co-polymers as used herein alsorefers to co-polymers wherein the further alk-1-ene having up to 10carbon atoms is incorporated randomly. In these co-polymers in generalthe co-monomer content is less than about 15% by weight. The copolymersmay also be in the form of so-called block or impact copolymers, whichin general comprise at least a matrix of a propylene homo polymer orpropylene random co-polymer containing less than 15% by weight of afurther alk-1-ene having up to 10 carbon atoms and a soft phase of apropylene co-polymer (rubber phase) containing 15% to 80% by weight offurther alk-1-enes having up to 10 carbon atoms. Also, mixtures ofco-monomers are contemplated, resulting in, for example, ter-polymers ofpropylene.

The production of propylene polymers may be carried out in any commonreactor suitable for the polymerization of alk-1-enes, either batchwiseor, preferably, continuously, i.e., in solution, as suspensionpolymerization including the bulk polymerization in liquid monomer, oras gas phase polymerization. Examples of suitable reactors includecontinuously stirred reactors, loop reactors, fluid bed reactors, andhorizontal or vertical stirred powder bed reactors. It will beunderstood that the polymerization may be carried out in a series ofconsecutively coupled reactors or in at least two reactors in parallel.The reaction time depends on the chosen reaction conditions. In general,the reaction time is from about 0.2 to about 20 hours, usually fromabout 0.5 to about 10 hours most preferably between 0.5 and 2 hours.

In general, the polymerization is carried out at a temperature in therange of from about 20° C. to about 150° C., preferably from about 50°C. to about 120° C., and more preferably from about 60° C. to about 95°C., and a pressure in the range of from about 1 to 100 bar, preferablyfrom about 15 to about 50 bar, and more preferably from about 20 toabout 45 bar.

The molecular weight of the resulting polymers may be controlled andadjusted over a wide range by adding polymer chain transfer ortermination agents as commonly used in the art of polymerization, suchas hydrogen. In addition, an inert solvent, such as toluene or hexane,or an inert gas, such as nitrogen or argon, and smaller amounts of apowdered polymer, e.g., polypropylene powder, may be added.

The weight average molecular weights of the propylene polymers producedby using the catalytic systems described herein in general are in therange of from about 10,000 to 2,000,000 g/mole and the melt flow ratesare in the range of from about 0.01 to 2000 g/10 min, preferably fromabout 0.1 to 100 g/10 min. The melt flow rate corresponds to the amountwhich is pressed within 10 minutes from a test instrument in accordancewith ISO 1133 at a temperature of 230° C. and under a load of 2.16 kg.Certain applications might require different molecular weights thanmentioned above and are contemplated to be included within the scope ofembodiments herein.

The catalytic systems described herein enable polymerization ofalk-1-enes producing polymers having a good morphology and a high bulkdensity when compared with the prior art catalytic systems. In addition,the catalytic systems may show a dramatic increase of productivity.

Catalytic systems using diether internal donors according to embodimentsherein may be used to produce propylene homo polymers and copolymershaving a xylene solubles content range of between 0.5 and 10 wt %, whichcannot be achieved by prior art catalyst systems including diethers asan internal donor. For example, catalytic systems described herein maybe used to produce a propylene polymer having a xylene solubles contentof about 1.0 wt % in some embodiments; greater than 2 wt % in otherembodiments; and greater than 4 wt % or 6 wt % in yet other embodiments.Catalyst systems disclosed herein may be used to produce multiple gradesof propylene polymers having xylene solubles content in the range fromabout 0.5 wt % to about 10 wt % in some embodiments; in the range fromabout 1 wt % to about 6 wt % in other embodiments; and in the range fromabout 1.5 wt % to about 5 wt % in yet other embodiments. The variationin the xylene solubles may be achieved in some embodiments by varying anamount of one or both catalyst components, as discussed above.Advantageously, the broad range of propylene polymers may be producedaccording to embodiments herein by varying the relative amounts of thecatalyst components and/or by adjustment of diether internal electrondonor content. As a result, the compatibility of feed components (i.e.,not changing external donors, etc.) and other factors resulting fromcatalyst systems herein may provide significant benefits to overallplant operations, such as due to ease of grade transitions, reducedmaterials handling, and other factors as may be recognized by oneskilled in the art.

In the case of block or impact copolymers, which may be polymerizedusing the catalytic systems using diether internal donors according toembodiments herein in at least two polymerization steps and which ingeneral comprise at least a matrix of a propylene homo polymer orpropylene random co-polymer and a propylene co-polymer rubber, thexylene solubles content of the polymer is measured using a sample of thepropylene homo polymer or propylene random co-polymer. Such a sample canbe drawn from the polymerization after the homo polymer or randompolymer polymerization step(s) but before the propylene copolymer rubberpart is produced. Such propylene homo polymer or propylene randomco-polymer matrix components have in some embodiments a xylene solublescontent in the range of 0.5 to about 3.5 wt % or 0.8 to 2.5 wt % and inthe range from about 1.0 to about 1.8 wt % in yet other embodiments.

The content of xylene solubles in the polymer is measured according toISO 16152.

The xylene solubles may be separated by heating the polymer resin inboiling xylene. Upon cooling, the crystallisable part of the polymer isprecipitated. The non-crystallisable fraction remains dissolved, and isreferred to as the “xylene solubles” (XS).

Due to their good mechanical properties, the polymers obtainable byusing the catalytic systems disclosed herein, and in particular thepropylene homo polymers or the co-polymers of propylene with one or morealk-1-enes having up to 10 C-atoms, can be used advantageously for theproduction of pipe, film, fiber or moldings and in particular for theproduction of film.

EXAMPLES

Catalyst Synthesis

The general procedure and the equipment used for the synthesis of thecatalyst components are described in patent application WO 2009/152268A1, which is incorporated herein by reference to the extent notcontradictory with embodiments disclosed herein.

Catalysts were made using sixty micron support (d50) with a span[d50/(d90−d10)] of 0.8 of spherical MgCl₂-xEtOH, where x is 3.1. If notmentioned otherwise, for each catalyst preparation a mixture of 70 wt %TiCl₄ and 30 wt % heptane were initially charged to the glass reactorand cooled down to temperatures of about −5° C. Then the MgCl₂-3.1EtOHsupport was added over a period of about 45 minutes while maintainingtemperatures below 0° C. The molar ratio of Mg/Ti used is provided foreach catalyst below.

While the actual quantities of the initial charges vary slightly foreach catalyst preparation run, the initial charge was based on using 10g of MgCl₂-3.1EtOH support, unless noted otherwise. After the MgCl₂support addition, the temperature was increased at approximately 1° C.per minute to 50° C. or to 80° C. Then the internal donor (ID), e.g.diether or D-i-BP (di-i-butyl phthalate) was added. The molar ratio ofthe internal donor (ID) to Mg is provided for each catalyst below.

If not mentioned otherwise, the suspension was then heated to 105° C.and held there for 1 to 3 hours. Afterwards the reactor contents weretransferred to a Soxhlet extraction device, filtered while still hot andthen washed with heptane. Then the precatalyst was Soxhlet-extracted forapproximately 2 hours with a 90/10 volume mixture of ethylbenzene andTiCl₄ at the boiling temperature of the mixture. After extraction thecatalyst was washed three times with 100 ml heptane and vacuum dried for2 h, which results in a residual solvent content of less than 2 wt % forthe catalytic components and comparative catalysts.

One or more parameters were varied for each catalyst preparation. Theparameters used and any change from the procedure are noted in thefollowing.

Synthesis of the Catalytic Components

Catalytic Component 1:

The molar ratio of Mg/Ti was 1:21. As internal donor2-isopropyl-2-isopentyl-dimethoxypropane with an ID/Mg ratio of 0.25 wasadded at 80° C. The suspension was allowed to react at 105° C. for 1.5hours.

Catalytic Component 2:

The molar ratio of Mg/Ti was 1:21. As internal donor2-isopropyl-2-isopentyl-dimethoxypropane with an ID/Mg ratio of 0.35 wasadded at 80° C. The suspension was allowed to react at 105° C. for 3hours.

Catalytic Component 3:

The molar ratio of Mg/Ti was 1:20. As internal donor2-isopropyl-2-isopentyl-dimethoxypropane with an ID/Mg ratio of 0.25 wasadded at 80° C. The suspension was allowed to react at 105° C. for 3hours.

Catalytic Component 4:

The molar ratio of Mg/Ti was 1:20. As internal donor2-isopropyl-2-isopentyl-dimethoxypropane with an ID/Mg ratio of 0.15 wasadded at 80° C. The suspension was allowed to react at 105° C. for 3hours.

Catalytic Component 5:

The molar ratio of Mg/Ti was 1:20. As internal donor9,9-Bis(methoxymethyl)fluorene with an ID/Mg ratio of 0.15 was added at80° C. After addition of the internal donor the suspension was held at80° C. for 1 hour. Then the suspension was allowed to react at 105° C.for 1 hour.

Catalytic Component 6:

The molar ratio of Mg/Ti was 1:20. As internal donor9,9-Bis(methoxymethyl)fluorene with an ID/Mg ratio of 0.25 was added at80° C. After addition of the internal donor the suspension was held at80° C. for 1 hour. Then the suspension was allowed to react at 105° C.for 1 hour.

Catalytic Component 7:

The molar ratio of Mg/Ti was 1:20. As internal donor9,9-Bis(methoxymethyl)fluorene with an ID/Mg ratio of 0.25 was added at80° C. After addition of the internal donor the suspension was held at80° C. for 1 hour. Then the suspension was allowed to react at 105° C.for 3 hour.

Catalytic Component 8:

The molar ratio of Mg/Ti was 1:21. As internal donor9,9-Bis(methoxymethyl)fluorene with an ID/Mg ratio of 0.20 was added at80° C. After addition of the internal donor the suspension was held at80° C. for 1 hour. Then the suspension was allowed to react at 105° C.for 1 hour.

Catalytic Component 9:

The molar ratio of Mg/Ti was 1:10, while 20 g of the support was addedover 90 min. As internal donor 9,9-Bis(methoxymethyl)fluorene with anID/Mg ratio of 0.25 was added at 80° C. After addition of the internaldonor the suspension was held at 80° C. for 1 hour. Then the suspensionwas allowed to react at 105° C. for 3 hour.

Catalytic Component 10:

The molar ratio of Mg/Ti was 1:21. As internal donor9,9-Bis(methoxymethyl)fluorene with an ID/Mg ratio of 0.15 was added at50° C. After addition of the internal donor the suspension was held at50° C. for 1 hour. Then the suspension was allowed to react at 105° C.for 1.5 hour. After heptane wash the precatalyst was not Soxhletextracted. Instead the solid was treated two times with 150 ml TiCl4 at125° C. for 2 hours.

Catalytic Component 11:

The molar ratio of Mg/Ti was 1:10, while 20 g of the support was addedover 90 min. As internal donor 9,9-Bis(methoxymethyl)fluorene with anID/Mg ratio of 0.25 was added at 80° C. After addition of the internaldonor the suspension was held at 80° C. for 1 hour. Then the suspensionwas allowed to react at 105° C. for 1 hour. After ethylbenzene wash theprecatalyst was not Soxhlet extracted. Instead the solid was treated twotimes with a mixture of 50 ml TiCl4 and 100 ml ethylbenzene at 125° C.for 2 hours.

Synthesis of Non-Inventive Catalysts Using Phthalate as Internal Donor(ID)

Comparative Catalyst A:

The molar ratio of Mg/Ti was 1:10, while 20 g of the support was addedover 90 min. As internal donor di-iso-butyl-phthalate with an ID/Mgratio of 0.25 was added at 50° C. After addition of the internal donorthe suspension was held at 50° C. for 1 hour. Then the suspension wasallowed to react at 105° C. for 1.5 hour.

Comparative Catalyst B:

The molar ratio of Mg/Ti was 1:10, while 20 g of the support was addedover 90 min. As internal donor di-iso-butyl-phthalate with an ID/Mgratio of 0.15 was added at 50° C. After addition of the internal donorthe suspension was held at 50° C. for 1 hour. Then the suspension wasallowed to react at 105° C. for 1.5 hour.

The titanium, magnesium and carbon content by weight percentage of thecatalytic components are summarized in table 1. The comparative examplesare found at the bottom of the table.

TABLE 1 Ti, Mg AND C - CONTENT OF CATALYTIC COMPONENTS Catalytic Ti Mg CComponent [wt. %] [wt. %] [wt. %] 1 2.2 17.8 15.9 2 2.4 17.6 15.4 3 2.417.5 15.7 4 4.9 16.1 13.5 5 3.8 14.7 19.6 6 2.6 14.8 25.1 7 3.4 13.126.4 8 3.2 14.2 22.9 9 3.5 14.5 24.3 10  4.7 14.2 22.6 11  2.4 14.7 25.6Comp. catalyst A 3.6 13.7 18.4 Comp. catalyst B 2.0 17.9 11.5

Polymerization Testing

The performance of the catalyst components and the catalyst systems incomparison with the comparative phthalate based catalysts was testedunder both bulk polymerization and gas phase polymerization conditions.

If not mentioned otherwise, bulk polymerization testing was performedusing a 5-liter reactor equipped with a helical stirrer, 1800 grams ofpropylene, optionally 2.0 ml external electron donor compound, 9.0 ml of1.3 M triethylaluminum (TEAl), and 0.5 grams of hydrogen, which wereadded to the reactor at 25° C. in the following order: after addition ofhydrogen, TEAl and optionally silane were premixed and then flushed intothe reactor using 900 grams of propylene. The last components added werethe ˜0.01 grams of catalyst using the remaining 900 grams of propylene.Under constant stirring at 200 rpm, the reactor was then heated quicklyto 70° C., usually within 10 minutes, and the polymerization run wasallowed to proceed for 1 hour in liquid propylene as suspension medium.

The same bench scale reactor which was used for the bulk polymerizationswas used for the gas phase polymerizations. If not mentioned otherwise,under gas phase conditions the order of addition was the same, but thepropylene charges are reduced in size to ˜180 grams, while 2.5 ml TEAl,optionally an external donor compound and 0.5 g hydrogen were added. Thecatalyst was injected at 40° C. and the reactor programmed to heat to75° C. over 10 minutes. Gas phase conditions were maintained bycontrolling the introduction of the propylene into the system. As thesystem was heated up to final temperature, the propylene was added at arate to ensure that the pressure in the reactor vessel is such that thepropylene always remains in the gas phase. To insure gas phaseconditions, the reactor pressure was maintained at 26.7 bar at 75° C.with gaseous propylene being added though a mass flow meter upon demand.

As external donors, donor compounds cyclohexyl-(methyl)-dimethoxysilaneand dicyclopentyl-dimethoxysilane were used; below indicated by C and D,respectively. Furthermore, the diether compound2-isopentyl-2-isopropyl-dimethoxypropane was also used as externaldonor. For the polymerizations, all external donors were diluted withheptane, obtaining a 0.1 M solution.

When, according to the invention, a catalytic system is used to controlthe stereo selectivity, the relative mass ratio of the catalystcomponents (RSC) based on the sum of all catalyst components ismentioned. Thus the following equation can be applied:RSC=m(A)/[m(A)+m(B)+m(C)+ . . . +m(Z)]

where:

-   -   RSC=relative mass ratio of the catalyst components    -   m(A)=mass of the catalytic component, controlling the stereo        selectivity and producing a homo polymer with a XS lower than 2        wt. %    -   m(B), m(C), . . . , m(Z)=mass of catalytic component, producing        a homo polymer with a XS greater than 2 wt. %        For example the relative mass ratio (RSC) is 0.2 when using 8 mg        of a first catalyst component producing a homo polymer with a XS        greater than 2 wt. % and 2 mg of a second catalyst component        producing a homo polymer with a XS lower than 2 wt. %. To        constitute the catalyst system, the catalyst components were        premixed before introduction into the reactor vessel.

The physical characteristics of the polypropylene polymers producedusing the various catalyst components and/or catalyst systems weredetermined using the tests described below.

Activity.

The activity results reported throughout this study are based uponpolymer yield in kilograms divided by the weight of the catalyst systemcharged to the reactor in grams for a 1-hour polymerization.

Xylene Solubles (wt % XS).

Xylene solubles were measured using Viscotek's Flow Injector PolymerAnalysis (FIPA) technique which is well known in the industry. Viscotekhas published an article entitled, “FIPA for xylene solubledetermination of polypropylene and impact copolymers” (which may beordered from the Viscotek website,http://www.viscotek.com/applications.aspx) showing that the ViscotekFIPA method exhibits a 0.994 r² correlation with ASTM Method D5492-06(equivalent to ISO 16152) over the range of 0.3% to 20% Xylene solubles.Therefore, one of ordinary skill in the art could reproduce theinventive results using either the Viscotek FIPA method or ASTM MethodD5492-06. The weight percent of xylene solubles in the polypropylene isan indication of the stereoregulating ability of the catalyst componentor catalyst system—the higher the wt % XS, the lower thestereospecificity of the catalyst. While higher XS values are requiredfor applications like the BOPP film production process, low XS valuesare of value for applications like injection moulding.

Melt Flow Rate (MFR) Measurement.

The melt flow rate effect was measured using ASTM Method D 1238-04. Foreach 5 gram sample of polymer, 0.2 grams of a standard stabilizingpackage was added. The additive package consists of 50 wt. % Irganox1010 and 50 wt. % Irgafos 168. Because the polymer is exposed to air at230° C. for several minutes during the test, this package is added toinhibit thermal and oxidative degradation of the polymer. The melt flowrate provides information concerning the molecular weight and thehydrogen response of the polymer. The higher the MFR, the higher thehydrogen response rate of the catalyst that produced the polyolefin.Similarly, the higher the MFR, the lower the molecular weight of thepolymer.

Molecular Weight Distribution.

The Polydispersity Index (PI) was determined by rheology using a dynamicshear test, the so called Dynamic Oscillatory Rate Sweep (DORS). Asample in the form of a compression molded disk is loaded between aparallel plate-to-plate geometry. The measurements were performed atT=210° C. in a frequency range between 0.1 and 400 rad/s. ThePolydispersity Index (PI), which is correlated to the ratio of theweight (Mw) to number (Mn) average molecular weights, is calculated fromthe crossover modulus as follows: PI=10⁵ Pa/G_(c), where G_(c)=dynamicstorage modulus (G′)=dynamic loss modulus (G″) at the crossoverfrequency.

The Temperature Rising Elution Fractionation.

The temperature rising elution fractionation (TREF) of the polymersamples was performed by using an automated CRYSTAF-TREF 300 instrument(PolymerChar S.A., Valencia Technology Park, P.O. Box 176, Valencia,Va., E-46980, PATERNA, Spain), equipped with heated infrared (IR)concentration detector with composition sensor, and capillary viscometerdetector. Polymer solutions were prepared at a concentration of 3±0.25mg/ml in 1,2-dichlorobenzene (stabilized with 300 ppm2,6-di-tert-butyl-4-methylphenol) at 150° C. for 90 minutes. Afterdissolution step is finished the sample is automatically transferred tothe TREF column where the stabilization, crystallization and elutioncycles take place. During the stabilization the column is cooled downfrom 150 to 95° C. at 40° C./min and then isothermally kept at thistemperature for 45 min. The crystallization step is carried out bycooling down from 95° C. down to 35° C. at a cooling rate of 0.5°C./min. At the end of the crystallization step the column is stabilizedat 35° C. for 10 minutes. After this stabilization period the content ofthe column is eluted for 10 minutes to collect the soluble fraction. Theelution step is carried out from 35 to 140° C. at a heating rate of 1°C./min, while maintaining a constant solvent flow rate of 0.5 ml/min.Data acquisition and processing was done using the software provided byPolymerChar. The TREF plot was normalized to 100% integral including thesoluble fraction.

Activity of the Catalyst Components Based Upon Polymerization Testing

Tables 2 and 3 summarize the bulk and gas phase polymerization results,respectively, that were obtained solely with the catalytic componentsdescribed above. The usage of silane C as external electron donorcompound (ED) is indicated in column 3. The comparative examples arefound at the bottom of the tables.

TABLE 2 BULK PHASE POLYMERIZATION RESULTS Catalytic Activity MFR/ XS/Example Component ED [KgPP/g-cat.] [g/10 min] [wt. %] PI 1 1 — 73.5 52.40.7 4.1 2 2 — 79.1 46.7 1.2 4.0 3 3 — 68.7 89.0 1.9 4.0 4 4 — 61.5 136.39.1 5.2 5 6 — 54.6 81.9 2.2 4.2 6 7 — 89.4 64.6 3.8 4.0 7 8 — 63.1 66.53.7 4.1 8 9 — 81.3 90.4 3.7 4.0 9 10 — 54.3 121.3 8.8 4.1 10 11 — 53.574.6 1.4 4.0 Comp. 1 Comp. — 21.6 525.6 33.5 4.1 catalyst A Comp. 2Comp. C 47.1 31.1 2.2 4.2 catalyst A

TABLE 3 GAS PHASE POLYMERIZATION RESULTS Catalytic Activity MFR/ XS/Example Component ED [KgPP/g-cat.] [g/10 min] [wt. %] PI 11 1 — 35.4 9.31.2 4.5 12 2 — 31.3 8.2 1.8 3.7 13 3 — 31.8 10.8 2.4 4.0 14 4 — 28.622.9 9.4 4.3 15 5 — 38.0 26.9 6.3 3.9 16 6 — 43.3 20.0 1.7 3.8 17 7 —39.3 11.9 4.6 3.9 18 8 — 29.2 15.0 2.6 3.8 19 9 — 54.4 25.4 3.7 3.8 2010 — 39.1 21.3 7.0 3.8 21 11 — 31.5 16.2 1.7 4.0 Comp. 3 Comp. A — 16.661.9 29.3 4.0 Comp. 4 Comp. A C 30.4 10.0 1.2 3.9

The results in Table 2 and 3 clearly show that the exemplary diethercatalyst components of the present invention exhibited significantlyhigher activity and stereo selectivity without silane as externalelectron donor compound in the polymerization process than thecomparative catalysts A, while the polydispersity index (PI) issurprisingly comparable for all catalysts.

A high stereo selectivity with a catalyst containing phthalate, e.g.comparative catalysts A can be obtained only in the presence of anexternal electron donor compound. Simultaneously with the decrease ofthe XS value the activity increases significantly. Even under theseconditions the diether catalyst components show a comparable or evenhigher activity within a broad XS range. For example under bulkpolymerization condition catalyst component 6 shows an activity of 54.6kg/g-cat without any stereo modifier and comparative catalyst A shows anactivity of 47.1 kg/g-cat in the presence of a silane, while the XS andPI values of both homo polymers are comparable (see example 5 and comp.example 2).

The stereo selectivity of the catalyst components can be adjusted byvarious synthesis parameters. One is the amount of diether as internaldonor used for the synthesis, exemplary shown with catalytic components2 to 4 (see example 2 to 4 and 12 to 14). Here with increasing ID/Mgratio during the synthesis the stereo selectivity increases, resultingin lower XS value in the polymer, see table 2 and 3. Other exemplaryparameters are the reaction time and temperature (80 or 105° C.), theMg/Ti ratio as well as the applied activation procedure.

Table 4 summarizes comparative gas phase polymerization results thatwere obtained with the catalytic components of the present inventiondescribed above and a silane as non-inventive catalytic system. For thepolymerization 0.05 g of hydrogen and 0.3 ml silane were added. Asexternal electron donor compound the silanes C or D were used.

TABLE 4 NON INVENTIVE GAS PHASE POLYMERIZATION RESULTS CatalyticActivity MFR/ XS/ Example Component ED [KgPP/g-cat.] [g/10 min] [wt. %]PI Comp. 5 Comp. C 28.3 6.5 1.5 4.5 catalyst A Comp. 6 Comp. C 27.9 6.21.3 4.1 catalyst B Comp. 7 Comp. D 30.6 0.5 0.6 4.3 catalyst B Comp. 8 7C 25.2 5.8 2.9 4.3 Comp. 9 7 D 20.4 5.4 2.5 4.5 Comp. 10 6 D 15.3 6.51.1 4.1 Comp. 11 3 D 14.9 4.2 1.3 4.7 Comp. 12 1 D 17.7 3.2 0.9 5.0

Table 4 shows that in contrast to the comparative catalysts A and B inthe presence of a silane the activities of the diether based catalystcomponents decrease significantly, while the increase in stereoselectivity which can be translated with a decrease in the XS values isless pronounced. For example under gas phase polymerization conditionsthe usage of 0.3 ml of silane C causes a reduction of the XS from 29.3to 1.5 wt % for comparative catalyst A, while the activity increases bya factor of 1.7 (Comp. examples 4 vs. Comp. example 5). For catalyticcomponent 7 the XS decreases only from 4.6 to 2.9 wt % andsimultaneously the activity decreased by ˜40% (Example 17 vs. Comp.example 8).

The stereo selectivity as well as the activity of a catalyst containingphthalate as internal donor increases when replacing silane C by silaneD, which results in a further decrease of the XS value from 1.3 to 0.6wt % for comparative catalyst B (Comp. examples 6 vs. Comp. example 7).Nevertheless, even with silane D a XS value lower than 2.5 wt % cannotbe achieved with catalytic component 7 containing a diether as internaldonor (Comp. example 9). Thus for lower XS values another diether basedcatalyst component producing a lower XS value without the need to use anexternal electron donor has to be applied, e.g. catalytic components 1,3 or 6 (Example 11 vs. Comp. example 12; example 13 vs. Comp. example11; example 16 vs. Comp. example 10).

Table 5 compares the response of silane C with comparative catalyst Band catalytic component 7, while the amount of used silane is indicatedin column 1. The results are also shown in FIG. 2.

TABLE 5 NON INVENTIVE GAS PHASE POLYMERIZATION RESULTS XS Value ofAmount of 0.1M XS Value of catalytic comparative Example Silane [ml]component 7 [wt. %] catalyst B [wt. %] Comp. 13 0.05 4.5 15.9 Comp. 140.1 4.2 5.8 Comp. 15 0.2 3.9 1.5 Comp. 16 0.3 2.9 1.3 Comp. 17 0.5 2.61.0 Comp. 18 1.0 2.3 0.9 Comp. 19 2.0 2.2 0.9

Table 5 and FIG. 2 clearly show that the accessible XS range ofcatalytic component 7 containing diether as internal donor is limitedcompared to comparative catalyst B containing phthalate as internaldonor. Here with silane C the comparative catalyst B has an accessibleXS range between 16 to about 1 wt. %, while the diether catalystcomponent 7 is limited to a small range between 4.5 and 2.2 wt. %. Thuslow or higher XS products cannot be produced, which heavily restrictsthe accessible product range.

Additionally, FIG. 2 also shows the disadvantage of a catalytic systemcontaining phthalate as internal donor and silane as external electrondonor compound. Only a slight change of the amount of silane causes asignificant change in the XS value (Comp. example 13 vs. comp. example14 of comparative catalyst B). Such a behavior makes it ratherchallenging to run a commercial plant without considerable fluctuationof the XS content of the polymer.

Another external electron donor compound option could be an additionaldiether compound. Table 6 summarizes polymerization results obtainedwith catalytic component 1 and 2-isopentyl-2-isoproyl-diemethoxypropaneas external electron donor compound as non-inventive catalytic system.The amount of used external donor is indicated in column 2.

TABLE 6 NON INVENTIVE GAS PHASE POLYMERIZATION RESULTS Activity MFR/ XS/Example ED [KgPP/g-cat.] [g/10 min] [wt. %] PI Comp. 20 0.5 17.4 6.8 0.74.5 Comp. 21 1.0 18.4 6.1 0.6 4.5 Comp. 22 2.5 16.3 4.8 0.6 4.6

The results in table 6 show that it is possible to obtain lower XSvalues with a diether as external electron donor compound. But in termsof activity the same strong reduction occurs, comparable to silanes.Even when accepting a lower activity the adjustment of the XS valuewould be as difficult as with the combination of a phthalate catalystwith a silane as external electron donor compound.

Table 7 summarizes polymerization results of catalyst systems, where asecond catalyst component producing low XS polymer is used as stereoselectivity control agent instead of a silane or a diether. The relativemass ratio of the catalyst components (RSC) was set to 0.5.

TABLE 7 GAS PHASE POLYMERIZATION RESULTS USING A TWO CATALYTIC COMPONENTCATALYST SYSTEM 2nd Activity MFR/ Exam- Catalytic Catelytic [KgPP/ [g/XS/ ple Component Component g-cat.] 10 min] [wt. %] PI 22 4 2 30.4 14.55.6 4.0 23 5 6 39.7 20.4 3.9 4.0 24 7 6 42.7 14.7 2.8 3.9 25 8 1 29.312.2 1.9 4.3 26 10 6 41.0 20.7 4.7 4.2 27 10 11 34.3 19.1 4.5 4.0   28 *9 3 75.2 84.1 2.7 4.0 * Polymerization was performed under bulkconditions

As summarized in table 7 the different catalyst systems show highactivities, while the XS value can be varied by using two catalystcomponents. Surprisingly, a second diether based catalyst componentproducing a homo polymer with a XS lower than 2 wt % can replace thesilane acting as external electron donor compound, while maintaining thecatalysts activities.

Table 8 summarizes polymerization results of diether based catalystcomponent 4 in the presents of catalyst component 1 producing a homopolymer with a XS lower than 2 wt %. For the polymerization the H2concentration was set to 0.03 g, while the relative mass ratio of thecatalyst components (RSC) was varied as shown in column 2. The XS valuevs. RSC is also shown in FIG. 3.

TABLE 8 INVENTIVE GAS PHASE POLYMERIZATION RESULTS WITH CATALYST SYSTEMActivity MFR/ Example RSC [KgPP/g-cat.] [g/10 min] XS/[wt. %] 29 0.026.1 5.3 9.5 30 0.1 26.4 4.1 8.3 31 0.3 27.5 3.5 8.0 32 0.5 27.6 2.8 4.733 0.7 28.5 2.6 2.4 34 0.9 27.6 2.3 2.0 35 1.0 28.8 2.0 1.4

Surprisingly, using a second “low XS” diether based catalyst componentas stereo selectivity control agent, the XS values can be variedunexpectedly easy. Quite contrary to the expectations, there is a linearrelationship between the XS values and the amount of the stereoselectivity control catalyst, see FIG. 3. This broadens the XS range ofthe diether based catalyst component producing a homo polymer with a XSgreater than 2 wt. % significantly, while the upper and the lower XSvalue limitation is given solely by the catalyst components.

Temperature rising elution fraction (TREF) curves of examples 29, 32 and35 in the temperature region between 90 and 125° C. are shown in FIG. 4,which represent the distribution of the longest crystallizable/isotacticsequence in the chain of a polymer. The first and the latter examplesare the curves of polymer produced with the single catalytic components4 and 1, respectively, while example 32 is polymer produced with arelative mass ratio of the catalyst components (RSC) of 0.5.Additionally, the arithmetic average of the curves of example 29 and 35is shown, which would be expected for example 32 by one of ordinaryskill in the art.

The peak maximum of the elution temperature of example 32 is 115.6° C.,which is between the single components. The value fits well with theexpected arithmetical average (115.3° C.) of example 29 (114.2° C.) andexample 35 (116.4° C.), see also FIG. 4.

Quite contrary to expectations, no broadening of the curve of example 32is observed. Normally one of ordinary skill in the art would expect anincrease of the half width in the following order: example 35<29<32.Thus comparing the curve of example 32 and the expected arithmeticaverage in FIG. 4 the properties of a polymer evaluated by TREF aresomehow influenced by using a catalyst system where a catalyticcomponent producing low XS polymer is used for controlling the stereoselectivity.

Unexpectedly, FIG. 5 shows that using a two diether catalysts system(bold curves; examples 29, 32 and 35) the curve shape of the polymerevaluated by TREF is comparable to a phthalate catalyst and silanesystem (doted curves; Comp. examples 13, 14 and 16). Independent ofusing a silane or a diether catalytic component, with increasing amountof stereo selectivity control component in the polymerization themaximum elution temperature increases, which is accompanied by adecrease of the half-width.

As described above, embodiments disclosed herein provide for uniquecatalytic systems comprising a combination of at least two solidcatalytic components with diether compounds as internal donor, while onesolid catalytic component takes the role of the liquid external donor,e.g. alkoxysilane for controlling the stereospecificity of the polymer.Advantageously, embodiments disclosed herein may provide for improvedcatalytic systems of the Ziegler-Natta type with an excellent hydrogenresponse and stereoselectivity as well as an improved control of thestereospecificity where the xylene solubles content of the polymer canbe adjusted between 0.5 and 10 wt %. In addition, the catalyst has ahigh activity and allows the production of polymers of α-alk-1-eneshaving a good morphology and bulk density.

While the disclosure includes a limited number of embodiments, thoseskilled in the art, having benefit of this disclosure, will appreciatethat other embodiments may be devised which do not depart from the scopeof the present disclosure. Accordingly, the scope should be limited onlyby the attached claims.

What is claimed is:
 1. A process for polymerizing propylene, the processcomprising: contacting, in a polymerization reactor, propylene, andoptionally one or more comonomers, with a catalyst system to produce apropylene polymer, wherein the catalyst system comprises: a first solidcatalytic component comprising: a spherical MgCl₂-xROH support, where xis in the range from about 1 to about 10 and wherein ROH is an alcoholor a mixture of at least two different alcohols; a group 4-8 transitionmetal; and a diether internal electron donor; a second solid catalyticcomponent comprising: a spherical MgCl₂-xROH support, where x is in therange from about 1 to about 10 and wherein ROH is an alcohol or amixture of at least two different alcohols; a group 4-8 transitionmetal; and a diether internal electron donor; wherein a molar ratio ofdiether internal electron donor to Mg in the first solid catalyticcomponent is such that: the first solid catalytic component produces apropylene homopolymer having a Xylene Solubles (XS) value of greaterthan 2 wt %; and wherein a molar ratio of diether internal electrondonor to Mg in the second solid catalytic component is such that: thesecond solid catalytic component produces a propylene homopolymer havinga XS value of less than 2 wt %.
 2. The process of claim 1, furthercomprising varying a ratio of the first solid catalytic component to thesecond solid catalytic component to vary the XS value of the resultingpropylene polymer.
 3. The process of claim 1, further comprising varyingan amount of diether in at least one of the first and second solidcatalytic components to vary the XS value of the resulting propylenepolymer.
 4. The process of claim 1, wherein the process does not includefeeding an external electron donor to the polymerization reactor.
 5. Theprocess of claim 1, further comprising feeding the first and secondsolid catalytic components independently to the polymerization reactor.6. The process of claim 1, wherein a weight ratio of the first solidcatalytic component to the second solid catalytic component is in arange from about 100:1 to about 1:1.
 7. The process of claim 1, whereina weight ratio of the first solid catalytic component to the secondsolid catalytic component is in a range from about 10:1 to about 1.1:1.8. The process of claim 1, wherein the second solid catalytic componentis used in an amount between 0.01 wt % and 99.99 wt % relative to thefirst solid catalytic component.
 9. A process for polymerizingpropylene, the process comprising: contacting, in a polymerizationreactor, propylene, and optionally one or more comonomers, with acatalyst system to produce a propylene polymer, wherein the catalystsystem comprises: a first solid catalytic component comprising: aMgCl₂-xROH support, where x is in the range from about 1 to about 10 andwherein ROH is an alcohol or a mixture of at least two differentalcohols; a group 4-8 transition metal; and a diether internal electrondonor; a second solid catalytic component comprising: a MgCl₂-xROHsupport, where x is in the range from about 1 to about 10 and whereinROH is an alcohol or a mixture of at least two different alcohols; agroup 4-8 transition metal; and a diether internal electron donor;wherein the first solid catalytic component and the second solidcatalytic component individually produce a propylene homopolymer havinga Xylene Solubles (XS) value differing by 1 wt % or greater.
 10. Theprocess of claim 9, wherein the first solid catalytic component and thesecond solid catalytic component individually produce a propylenehomopolymer having a Xylene Solubles (XS) value differing by 2 wt % orgreater.
 11. The process of claim 9, wherein the first solid catalyticcomponent produces a propylene homopolymer having a XS value in therange from about 3 wt % to about 20 wt %, and wherein the second solidcatalytic component produces a propylene homopolymer having a XS valuein the range from about 0.1 wt % to about 2 wt %.
 12. The process ofclaim 9, wherein the first solid catalytic component produces apropylene homopolymer having a XS value in a range from about 4 wt % toabout 10 wt %.
 13. The process of claim 9, wherein the second solidcatalytic component produces a propylene homopolymer having a XS valuein a range from about 0.5 wt % to about 1.5 wt %.
 14. The process ofclaim 9, further comprising varying a ratio of the first solid catalyticcomponent to the second solid catalytic component to vary the XS valueof the propylene polymer.
 15. The process of claim 9, further comprisingvarying an amount of diether in at least one of the first and secondsolid catalytic components to vary the XS value of the resultingpropylene polymer.
 16. The process of claim 9, wherein the process doesnot include feeding an external electron donor to the polymerizationreactor.
 17. The process of claim 9, further comprising feeding thefirst and second solid catalytic components independently to thepolymerization reactor.
 18. The process of claim 9, wherein a weightratio of the first solid catalytic component to the second solidcatalytic component is in a range from about 100:1 to about 1:1.
 19. Theprocess of claim 9, wherein a weight ratio of the first solid catalyticcomponent to the second solid catalytic component is in a range fromabout 10:1 to about 1.1:1.
 20. The process of claim 9, wherein thesecond solid catalytic component is used at an amount between 0.01 wt %and 99.99 wt % relative to the first solid catalytic component.